The present invention relates to a new and distinct cultivar of Hydrangea macrophylla and will be referred to hereafter by its cultivar name, ‘Horthat’. ‘Horthat’ represents a new bigleaf Hydrangea, a perennial shrub grown for landscape use and as a potted plant.
‘Horthat’ derived from an ongoing controlled breeding program directed by the Inventor. An objective of the breeding program included developing a new cultivar of Hydrangea with flowers that are dark rose in color combined with other desirable straits.
‘Horthat’ arose from a controlled cross made by the Inventor in Boskoop, The Netherlands in May of 2009 between unnamed and unpatented proprietary plants in the Inventor's breeding program; reference no. 08-007-02 as the female parent and reference no. 08-016-02 as the male parent. ‘Horthat’ was selected as a single unique plant from amongst the resulting seedlings in August of 2016.
Asexual propagation of the new cultivar was first accomplished by stem cuttings by the Inventor in Boskoop, The Netherlands in August of 2011. Asexual propagation by stem cuttings has determined that the characteristics of the new cultivar are stable and are reproduced true to type in successive generations.